1. Field of the Invention
The present invention relates generally to an apparatus and method of locking and, more particularly, an apparatus and method for assembling and locking fixed dumbbells and barbells, wherein a threaded handle or bar is used in combination with individual plates, a solid block of cast iron or steel and a female type locking insert. These items are used to assemble and lock into place fixed permanent weight dumbbells and barbells.
2. Description of the Prior Art
Fixed dumbbells and barbells have been used for over 50 years in commercial exercise environments, i.e. health clubs, gyms, schools, YMCA""s, etc. The word, xe2x80x9ccommercialxe2x80x9d dictated high use and more punishment. The fixed method means that the adding or subtracting of weight is not possible by the user and the idea was to have pairs of dumbbells or sets of barbells in set increments such as 5 lb., 10 lb., 20 lb., 30 lb., etc. permanently fixed normally by the use of a handle or bar where individual weight plates are put on each end of a handle or bar. They are normally secured with either a washer and bolt or an end plate (which is a larger version of a washer used to conceal the bolt) and a bolt. The idea was to provide a safer method to do heavy training without the concern of the dumbbells or barbells coming loose and injuring the user. To improve this method a liquid thread locking compound, or similar nylon patch was put on the bolt to eliminate the bolt from loosening and backing out. This method works fairly well unless the internal threads are not free of oil and other residue upon initial installation. In this case the locking compounds never properly seal. With these methods repeated loosening and tightening diminish the holding power considerably whereas once loosened full strength cannot be achieved without reapplication of compounds. The shock from banging together during use and the dropping on the floor when the user is finished puts stress on the bolt causing it to loosen and back out. In many cases, especially on heavier sizes, this applied shock will cause the bolt to shear and therefore the dumbbells and barbells can come apart potentially causing injury to the user. In these methods individual plates are put on both ends of a handle or bar then the accepted measure for the length of the handle or bar is that the last plate must stick out past the handle or the bar so when tightened with either the washer or the end plate it will be tight. The danger is that there is an unsupported area between the end of the bar or handle and the bolt. Often the installer will consider it a sufficient and safe connection as long as the handle or bar is barely into the last plate which increases the stress during shock. The optimum way would have been to have each and every size weight increment have a handle or bar that was just below the last plate installed, therefore reducing the unsupported area to a minimum. This was never done due to the multiple handle or bar requirements. In addition, conventional castings have inconsistencies in thickness which would create even more handles or bars required. Even going to this extreme would not eliminate the blind unsupported area between the handle and the back of the washer or end plate.
In today""s methods there are approximately 10 sizes of dumbbell handles used and 10 sizes of barbell bars used serving as a xe2x80x9ccatch all method.xe2x80x9d These methods work but do not provide the highest degree of strength and safety. In some cases upon installation of the current methods the handle or bar may be near flush with the last plate installed prior to tightening and after a high degree of usage internal plate wear causes the handle to protrude past the last plate making tightening impossible. These current methods will only stay tight if the handle or the bar is below the last installed plate on each end. This is why many equipment owners find the problem of a bolt that is tight, but the plates are not. It is also considered optimum to have these plates remain tight and not spin. Lastly, it is very difficult and rare for the normal purchaser of these products to have the special tools required to remove broken bolts or even be able to tighten and loosen them.
Solid steel dumbbells have emerged as a solution to the conventional methods to eliminate this loosening and breaking problem. In this design, a pair of solid one piece slugs are welded to a handle or a bar. In this method, the disadvantage is that it requires precise methods of welding to ensure a strong safe bond. This method is more expensive than with the use of cast iron. With this style of dumbbell, the user will experience a sharp ringing sound when they make contact with each other which is not desirable. Until now, no dumbbell or barbell has been viewed as permanent other than this solid steel welded method.
Solid steel dumbbells have emerged as a solution to the conventional methods to eliminate this loosening and breaking problem. In this design a pair of solid one piece slugs are welded to a handle or bar. In this method, the disadvantage is that it requires precise methods of welding to ensure a strong, safe bond. This method is more expensive than with the use of cast iron. With this style of dumbbell, the user will experience a sharp ringing sound when they make contact with each other which is not desirable. Until now, no dumbbell or barbell has been viewed as permanent other than this solid steel welded method.
In summary as shown in FIGS. 1A-1C and FIGS. 2A-2B, those devices, methods and mechanisms of the prior art were not able to solve these issues. By enumerating not only the cause of the instant problem for each alternative design, but actually conceiving, reducing to practice and prototyping the instant invention the present inventor has both identified and overcome a longstanding problem in the weight-lifting arts.
According to a feature of the invention there is provided a process for securing weights on a barbell, which comprises the steps of: providing at least two locking nuts having fail-safe locking means, a bar or handle, and desired weight plates; disposing the desired weight plates at a fixed spaced relationship to each other; and tightening the at least two locking nuts by isolating the load from the nut body. An apparatus made by the process is likewise taught.
According to a further feature of the invention there is provided a novel enhanced dumbbell system, comprising, in combination: at least one of a handle and a bar; a plurality of weight plates; and a means for lockingly engaging a desired number of weight plates in a fixed spatial relationship about said at least one of a handle or bar.
This design uses a special threaded female body with an oblong spring steel insert that goes on under pressure which forces the insert to conform to the threaded shaft then, once applied pressure ceases it, retains its original oblong shape, which basically pinches the shaft and will not back off. The torque required is far less than previous methods. It may be loosened or tightened as needed. It is considered adjustable because if, for some reason, there was wear and the original surfaces of the plates wore away you could tighten the fastener slightly and it would be snug again. In conventional methods, a bolt is usually used with a thread locking compound or nylon patch on the threads. Both of these methods make loosening impossible without special tools and there is no forward adjustment. The new method virtually locks in place wherever you leave it. It can be used with individual plates or a solid block design of cast iron steel. The finishes could be paint, rubber or urethane coated. By using a 1.062 inch diameter threaded shaft in conjunction with the female locking device, there is no bolt to shaft connection. Individual plates or a solid block goes on each end and then held in place with a rubber end plate that acts like a washer that the female fastener snugs up against to form a tight bond (it is countersunk to hide fastener). In conventional methods, a xc2xd inch or ⅝ inch diameter bolt is used and various sized handles go through individual plates leaving a blind spot between the end of the handle and the back of the end plate. Under shock loads and constant banging or dropping is where failure occurs snapping bolts. With the new version the connection is far stronger with no blind or unsupported area and the actual shaft which replaces the bolt is much larger and far stronger than any existing bolt to handle method. Dumbbells in health clubs go up to 150 lbs. and over per handle. It would be very dangerous if they were to break over the head or body of the user.
Uniquexe2x80x94This design uses a special threaded female body with an oblong spring steel insert that goes on under pressure which forces the insert to conform to the threaded shaft then once applied pressure ceases it retains its original oblong shape which basically pinches the shaft and will not back off. The torque required is far less than previous methods. It may be loosened or tightened as needed. It is considered adjustable because if for some reason there was wear and the original surfaces of the plates wore away you could tighten the fastener slightly and it would be snug again. In conventional methods, a bolt is usually used with a thread locking compound or nylon patch on the threads. Both of these methods make loosening impossible without special tools and there is no forward adjustment. The new method virtually locks in place wherever you leave it. It can be used with individual plates or a solid block design of cast iron steel. The finishes could be paint, rubber or urethane coated.
Saferxe2x80x94By using a 1.062xe2x80x3 diameter threaded shaft in conjunction with the female locking device there is no bolt to shaft connection. Individual plates or a solid block goes on each end then held in place with a rubber end plate that acts like a washer that the female fastener snugs up against to form a tight bond (it is countersunk to hide fastener). In conventional methods, a xc2xdxe2x80x3 or ⅝xe2x80x3 diameter bolt is used and various size handles go through individual plates leaving a blind spot between the end of the handle and the back of the end plate. Under shock loads and constant banging or dropping is where failure occurs snapping bolts. With the new version the connection is far stronger with no blind or unsupported area and the actual shaft which replaces the bolt is much larger and far stronger than any existing bolt to handle method. Dumbbells in health clubs go up to 150 lbs. and over per handle. It would be very dangerous if they were to break over some ones"" head or body.
With the solid block design the weights can be calculated to allow for longer handle weights. In conventional methods, the weight is off in the larger sizes,as the dumbbell gets heavier (longer) so does the handle and with standard plates available, i.e. 2.5 lb., 5 lb., 7.5 lb., 10 lb. There is no way to adjust and as a result a 150 lbs. is as much as 5 lbs. overweight. With the use of a new 11.25 lb. weight also unique to the fitness industry, sizes from 100 lbs. to 150 lbs. can now be more accurate.
No other dumbbell uses this type of fastening device. No other dumbbell is considered adjustable and may be tightened further once assembled. No other dumbbell uses a shaft and a threaded female concept except some import low end sets where you actually change plates to increase or decrease weight, but this is not done in commercial environments. Those systems are not permanent and will loosen and back off. No other dumbbell uses a locking device that will not back off under shock and vibration. No other dumbbell or barbell uses a fastening device that locks wherever you leave it. No other fixed dumbbell or barbell is assembled in a manner where the handle or bar goes completely through the individual plates, solid block and end plate whereas the end plate acts as only a washer instead of a supporting member. No other fixed dumbbell or barbell is used in a solid block design where a female locking insert retains the handle or bar to the block. This new method is stronger by several times over any current fixed method of individual component fastening. No other fixed method can be manipulated with the same degree of ease. This method also accommodates for inconsistencies in plate or block thickness.
The industry and the customer often choose solid steel dumbbells where two solid ends are welded to a handle. This was devised to eliminate loosening and breaking. The negatives are that you cannot use cast iron, only steel. If the welding is not done properly they have been known to snap off at the weld and also when they bang together they ring. Cast iron is more dead sounding and by using the rubber end plate the ringing goes away and the end plate protects the finish. We will also produce this with a paint, rubber or urethane coating.